1. Field of the Invention
The present invention relates to a document feeding mechanism, more specifically, to a document feeding mechanism with a floating input tray.
2. The Related Art
Please refer to FIG. 1 and FIG. 2. A conventional document feeding mechanism 900 includes a frame 902, a document picking up means 904, a driving means 906 and a pair of document blocking means 908. The document picking up means 904, the driving means 906 and the document blocking means 908 are configured to the frame 902.
The driving means 906 includes a motor 910 and a driving shaft 912. The driving shaft 912 interconnects the motor 910 and the document picking up means 904 for transmitting a driving force from the motor 910 to drive the document picking up means 904. The frame 902 includes a document supporting platform 914 formed at a front portion thereof for supporting documents and a pair of grooves 916 formed at a central portion thereof for receiving the document blocking means 908.
The frame 902 and the document picking up means 904 together define a document conveying path (not shown in figures) therebetween. The document picking up means 904 includes a supporting frame 918, a picking up unit 920, a separating unit 922, a transmitting unit 924 and a spring 926. The supporting frame 918 includes a pair of side walls 928, a tube 930 laterally protruded from a rear portion of one of the side walls 928 and a pair of blocks 932 laterally protruded from a front portion of the side walls 928.
The picking up unit 920 and the separating unit 922 are respectively coupled to the front portion and the rear portion of the supporting frame 918. The driving shaft 912 of the driving means 906 passes through the tube 930 of the supporting frame 918 and connects to the separating unit 922. The spring 926 is positioned in the tube 930 of the supporting frame 918 and surrounding the driving shaft 912 of the driving means 906.
Each of the document blocking means 908 includes a connection portion 934, a blocking arm 936 extended downwardly from the connection portion 934 and a pair of restricting arms 938 extended upward from the connection portion 934 respectively. The blocking arm 936 is extended into the groove 916 and drooped by gravity thereof for blocking the documents.
If the document feeding mechanism 900 works, then the picking up unit 920 of the document picking up means 904 will be raised at a predetermined level by the driving force from the driving means 906. The picking up unit 920 is held at the predetermined level because the spring 926 abuts against the tube 930 to form a friction therebetween.
The block 932 of the supporting frame 918 blocks the restricting arm 938 of the document blocking means 908 for restricting rotatable angle of the document blocking means 908. Since, the documents can be blocked outside the document conveying path by the document blocking means 908.
However, the restricting arm 938 of the document blocking means 908 may move beyond the block 932 of the supporting frame 918 if the blocking arm 936 of the document blocking means 908 is pushed exceedingly. Therefore, the document will intrude into the document conveying path to cause an erroneous work.